A verbal is a verb that acts like a different part of speech. Infinitives, gerunds, and participles are all types of verbals. An infinitive is a verbal consisting of to + a verb, and it acts like a subject, direct object, subject complement, adjective, or adverb in a sentence.
HeadOn is the brand name of a topical product claimed to relieve headaches. It achieved widespread notoriety in 2006 as a result of a repetitive commercial, consisting only of the tagline HeadOn. Apply directly to the forehead, stated three times in succession.
I'm not sure what movie you refer to, but generally speaking, a dead head is a follower of the great Jerry Garcia and the Greatful Dead. It can also refer to the act of removing dead blossoms from a plant, but I think in the case you refer to, the former would apply. Have a greatful day. This Site Might Help You.